A guide to keeping tropical fish

A guide to keeping tropical fish





Tropical fish are unique, incredibly fun to have as a pet and make a great addition to your family. The best part is you can add whatever you want into your home aquarium, but it is important to maintain different factors inside, so here is a guide so you can provide the best care they deserve!


Setting up your tank

When setting up your tank it can be an extremely exciting time. Be sure that ornaments and plants do not have any sharp edges that your fish could injure themselves on, and do not go overboard, your fish will want plenty of space to openly swim around. The size of the aquarium depends on the fish you will be keeping and how many you would like to purchase. It is recommended to start with a 75 litres aquarium and only adding one fish to ensure the tank is being cycled properly and the equipment is working efficiently.

When deciding where to place your aquarium think about avoiding direct sunlight, areas where they could be disturbed by noise and any heaters or windows that could interfere with the temperature.

Your tank needs special care so here are a few factors you need to consider when keeping tropical fish:

  • Temperature: 23-27°C
  • pH: 5-7.5
  • Nitrate: 5-10ppm
  • Nitrite: 0-0.5 ppm
  • Ammonia: 0 ppm

*Dependent on the fish species you wish to keep

Supplies list

  • Aquarium/tank
  • Filter
  • Lighting
  • Testing kits
  • Gravel & gravel siphon
  • Water conditioner & bacterial agents to de-chlorinate tap water
  • Plants & greenery
  • Food
  • Ornaments
  • Rocks
  • Airstone & pump
  • Aquarium heater & thermometer
  • Algae scraper/magnetic glass cleaner
  • Fish net



Tropical fish come in a large variety therefore it is important to provide them with the best diet. Fish either spend time swimming at the bottom, middle or top of the tank, which helps when choosing the most suitable food for them.

It is important not to overfeed your fish as this is the most common cause of tropical fish death and can also make the water polluted. It is recommended to only feed how much they can eat in 3 - 5 minutes. Some fish like pellets or flakes, but some may prefer frozen fish food. However, it is important to research the specific fish species to ensure you provide them with the best diet.

  • Carnivores

These meat-eaters love a protein-rich diet which includes bloodworms, krill, and brine shrimp.

  • Herbivores

These fish prefer live plants and vegetables that you can buy at your local supermarkets.

  • Omnivores

Most aquarium fish eat both meat and plants/vegetables.

Cleaning & maintenance

Every day visual checks should be carried out to ensure your fish are happy and healthy. Make sure all the equipment is functioning properly and clean the filter sponge, so nothing is clogging the filter. Look to see if there are any dead fish and/or plants and remove them from the tank.

Every week remove 20-25% of the water and replace it. Before you add the new water to the tank, check the water quality with a testing kit and never remove all the water as healthy bacteria builds up over time in the tank. Be sure to clean the sides of the tank and light tubes to remove any excess algae growth. A magnetic scraper and siphon can be used to keep the aquarium clean.

Every month ornaments and rocks should be cleaned of debris build-up.

Do not forget to check supplies and the performance of the filter monthly to ensure you can maintain a healthy environment for your fish.


Health care

Diseases are not uncommon when caring for fish, so it is vital to keep a close eye on them, so they do not get sick. Before purchasing your new fish and bring them home, be sure to check for any injuries or diseases.

Here are some common diseases/injuries in tropical fish:

  • Dropsy: Very fatal to tropical fish, the fish’s stomach will become bloated and they will stop eating.
  • Fin/tail rot: Your fish’s fins and/or tail will become frayed and start to turn white at the ends. They may also lose their appetite and sink to the bottom of the tank.
  • Cottonmouth: This is a bacterial infection where white/grey spots will appear on the fish’s head and mouth. Lesions can also be seen on the fish’s back.
  • Ammonia poisoning: Fish will be seen gasping at the surface of the tank with red or inflamed gills.
  • Holes in the head: Most common in cichlids, this disorder is usually from poor-quality food and contaminated water. Lesions will appear on the fish’s head.
  • White spot: This is a very contagious parasitic disease where the parasite feeds on the cells and body fluid of the fish. White spots will appear on the fish’s scales and they may sit at the bottom of the tank, if untreated it can be fatal.
  • Popeye: Fluid builds up behind the eye and is common when fighting occurs in the tank or because of poor water quality.
  • Slime disease/gill flukes: Mucus builds up over the gills and causes difficulty breathing.
  • Swim bladder disease: The fish can be seen swimming upside-down, sinking to the bottom or floating to the top of the tank. The cause is usually from a physical injury or poor nutrition.


Once one fish is infected the whole tank is at risk. You should separate the infected fish and put them into quarantine until they are feeling better to join their tank-mates.


Choosing fish for your tank

Not all fish can be friends with each other. It is important to find the best compatibility to reduce stress and injuries. Aggressive fish need to be kept with specific species, so it is best to ask your local fish shop who they can share a tank with if you are unsure. Even when fish are seen compatible, it is important to closely watch them when you introduce them into the tank. 

Fish should be added gradually, and the aquarium must not become overcrowded. When adding new fish allow the bag to float for at least 15 minutes so the temperature is equalised to reduce stress levels.

Here are a few popular tropical fish that are great to start with:


Lifespan 3 – 5 years



Lifespan 2 – 5 years



Lifespan 10 – 15 years



Lifespan 1 – 5 years



Lifespan 3 – 5 years






Lifespan 3 – 5 years



Lifespan 3 – 5 years